Known locking ring assemblies are available in a wide variety of configurations. All typically have a portion or an element disposed in an annular groove of the shaft with an adjusting mechanism disposed between the groove and a bearing to be retained on the shaft. The bearing is typically pressed by the adjusting mechanism against a shoulder of the shaft.
Retaining bearings on mill roll shafts and the like is complicated by the large size of the associated components and the resultantly high axial thrust loads required to maintain bearings in their desired positions. The design of locking ring assemblies for mill roll shafts is further complicated by the dirty, harsh operating environment in which they are employed. The intrusion of dirt and contaminants into undesired locations within a locking ring assembly can potentially affect its ability to maintain the required thrust load against the bearing.
One well known design for an adjusting mechanism consists of a pressure ring disposed on the shaft between the bearing and a snap ring or similar travel limit means disposed in a groove around the shaft. A plurality of jack screws or Jack bolts threadingly engaging the pressure ring in a direction parallel to the axis of the shaft extend beyond the pressure ring to contact either the bearing or an intermediate member therebetween. Turning of the jack screws develops a compressive load against the bearing which reacts against the shaft shoulder. With each of the plurality of Jack screws fully torqued, a sufficiently high axial thrust load can be developed against the bearing.
In the case of adjusting mechanisms having Jack screws disposed directly against the bearing to be retained, there is a possiblity that even with relatively dirt free components, the pressure ring may be cocked during the tightening of the jack screws, particularly if the Jack screws are tightened one at a time, thereby producing an uneven load distribution against the bearing. Additionally, if there is any dirt present between an end of the jack screw and the bearing, the resultant thrust load between the bearing and the Jack screw will significantly deteriorate should any of the dirt trapped therebetween become displaced. Additionally, dirt collecting on the extended threads of the screws can potentially damage the threads on both the screws and pressure ring when the screws are loosened.
There is a need in the field of locking ring assemblies to provide an adjusting mechanism which is relatively insensitive to contamination in a dirty environment.